Description:Haworthia coarctata v chalwinii is one of the morphological or geographical form of the coarctata group. It is a small plant which grows many upright leaf-clad stems radiating from an offsetting base, rather than flattened rosettes. It is not readily distinguishable from Haworthia coarctata var. coarctata, if not for the provenance and, may be, for the firmer leaves, each about 12-25 mm long and 5-20 mm broad at the base. The leaves are dotted with white, slightly raised, tubercles. Its leaf colour can vary from green to reddish brown dependant upon the amount of light it receives.Habit: This is a small evergreen tall rosette-succulent and forms dense clusters.Rosette: Columnar, tight, 5-20 cm tall, and about 4 cm in diameter, offsetting from the base. The leaves are seemingly arranged in many spiral rows around the stem.Leaves: About 25 mm long cm long, triangular-lanceolate, tips incurved, shining green, turning red in full-sun with greenish white slightly raised, rounded tubercles in longitudinal or sometimes transverse rows; density of tubercles very variable. Inflorescence (racemes): Up to 30 cm tall, usually unbranched, few-flowered. The flowers are white tubular.Blooming season: Spring to summer.Chromosome number: 2n=28 (It is also known an aneuploid variant with 2n=26.)

Subspecies, varieties, forms and cultivars of plants belonging to the Haworthia coarctata group

Haworthia coarctata var. tenuis(G.G.Sm.) M.B.Bayer: has rosettes half the diameter of var. coarctata up to 45 cm tall trailing and rooting where they touch the soil. Distribution: Harvestvale on the Bushmans River.

Cultivation and Propagation: Haworthia coarctata f. chalwinii is a proliferous species of easy cultivation and relatively low maintenance, forming clumps in nature. Its interest lies in its ability to change colour: in cooler weather the plant blush bronze-red. It is also a good houseplant, and can be an excellent subject for the beginning succulentophile (they can grow easily on window sills, verandas and in miniature succulent gardens where they are happy to share their habitat with other smaller succulent plants, or in outdoor rockeries). It is a winter grower and is dormant in the hottest summer months. In cultivation it needs more sunny position to show its beauty. Growth rate:Haworthia coarctata are relatively slow-growing plants that offsets freely to form small clusters whit time.Soil: They are tolerant of a wide range of soils and habitats, but prefer a very porous potting mix to increase drainage. A non-acid soil is ideal. You can grow a plant in a 10-15 cm pot for years and have perfectly happy plants. For best results, use a shallow pot. Exposition: The plant needs little bit more exposed situation to let plants grow compactly. With some sun exposure the leaf develops a nice reddish tint and remains compact. Watering: During the hot summer months, the soil should be kept moist but not overly wet. During the winter months, water only when the soil becomes completely dry. Wet soil quickly causes root and stem rot, especially during chilly winter months. No water should ever be allowed to stand around the roots. Low ambient humidity is always needed. Fertilization: The plants are fertilized only once during the growing season with a balanced fertilizer diluted to ½ the recommended strength. Hardiness: Although the plant will survive mild frost if kept dry (hardy as low as -5° C) it should be protected from severe cold and prolonged frost conditions. Rot: Rot is only a minor problem with Haworthia if the plants are watered and “aired” correctly. If they are not, fungicides won't help all that much. Care must be given in watering, keeping them warm and wet while growing, and cooler and dry when dormant. Remarks: Haworthias are best planted in a shaded and airy part of the greenhouse, and not too close to the glass roof or sides of the house as the plants can overheat during hot spells.Propagation:Haworthia are easily propagated by the removal of offshoots in spring or summer. They can also be grown from seed.